Roman coins are a valuable asset to any coin collection, but dirty coins can prevent you from enjoying these pieces of antiquity. Fortunately, there are simple ways to clean Roman coins. One of the most important parts of cleaning is to remove only the dirt, not the patina. Roman coins develop a patina over time that makes them more valuable, and removing it can lessen the coin's worth.
Soak Roman coins in warm water with a small amount of gentle, grease-cleaning soap. Allow the coins to soak for several minutes to loosen dirt and grease. The soap will help to remove dirt without damaging the patina of the coin. Remove the coin from the water and scrub it gently with a toothbrush to remove any remaining loose dirt and debris. Soak the coin again and repeat the process as necessary.
Soaking Roman Coins
Soaking Roman coins in distilled water for several days can loosen grime without damaging the coins. Allow the coins to soak for two to three days. Use a toothpick or dental pick to clean out grime between the letters or around the figures printed on the coin. According to Roman Coins Online, placing a small amount of glue from a hot glue gun on grime can remove it, but this damages the patina and silvering.
Removing Stubborn Grime
If gentler treatments do not work, there are other methods for removing stubborn grime from a coin. When soaking in water does not work, soaking Roman coins in valve or olive oil can help, although the process takes longer. Place a coin in olive or valve oil for a few days and remove and dry it. Gradually lengthen the time in this oil "bath" until the coins have soaked for several months, then attempt to remove grime with a toothpick.